Research On Vulcanization Heating System For Steel Cord Core Conveyor Belt Joints

As the main energy source in China's energy structure,coal provides a strong guarantee for economic development.As a key equipment for coal transportation,the quality of belt conveyor affects coal mine safety and coal mine production efficiency.As a key part of belt conveyor to carry materials,accidents of belt breakage due to large coal impact,gangue collision and quality of vulcanized joints occur from time to time,which may lead to more serious secondary accidents.In order to improve the vulcanization quality of conveyor belt joints,this dissertation adopts silicone rubber heating sheet to provide heat source for conveyor belt vulcanization,analyzes the heat transfer process of conveyor belt vulcanization and the uniformity of vulcanization temperature,designs the resistance wire of silicone rubber heating sheet as multi-channel return type,and a conveyor belt joint vulcanization test platform was built,and the vulcanization temperature field was studied by numerical analysis and experiments.Firstly,the mathematical model of heat transfer from the heat source to the tape for vulcanization was established,and the model contains parameter variables such as specific heat capacity and thermal conductivity,and the change curves of thermal conductivity and specific heat capacity with vulcanization temperature and the heat of vulcanization reaction were obtained through experimental studies of these parameters,which can be modified to supplement the above model,and also through the test results of the three parameters of specific heat capacity,thermal conductivity and enthalpy change can be It can be seen that since the thermal conductivity of rubber is much smaller than that of aluminum alloy,in order to simplify the simulation model,only the heat transfer between the heat source and the heating plate is analyzed without adding the tape when the thermodynamic simulation is carried out.Secondly,based on the mathematical model of vulcanization heat transfer,the temperature field distribution of vulcanization heating under the conventional scheme was investigated,and the numerical analysis software Comsol was used to simulate it.Based on the temperature field distribution,the scheme of replacing the single-channel arrangement with a three-channel zigzag arrangement of silicone rubber heating plates was proposed.A three-level five-factor orthogonal test was designed for parameters such as the regional spacing of the heating sheet and the power of its channels,and the temperature distribution law of the heating plate was simulated for each scheme based on the solid heat transfer simulation technology,and the extreme difference analysis was performed to arrive at the best design scheme and the largest factor affecting the temperature uniformity of the heating plate.It was found that the most significant factor affecting the surface uniformity of the heating plate was the edge heat flow density,and then ANOVA was applied to analyze and verify the regression equation between the values of the heating plate temperature uniformity index and the values of the factors was derived.Finally,a test platform for vulcanizing joints by silicone rubber heating was built,which was divided into a vulcanization temperature monitoring platform and a vulcanization heating test platform.The monitoring platform was studied from the horizontal direction,and the temperature sensors were evenly arranged on the heating plate so as to grasp the distribution of the temperature field on the surface of the heating plate.When the temperature of one of the temperature measurement points reaches the set maximum vulcanization temperature,the silicone rubber heater stops heating and the temperature value of each temperature measurement point of the heating plate is obtained to judge the uniformity of the heating plate surface,and the temperature change curve of each temperature measurement point with time is also obtained to compare the simulation results for physical test verification and research.Compared with the original single-channel heating method,the temperature difference of the heating plate surface is reduced from 12? to 3.8?,which proves the effectiveness of the design solution.